Engine/Transmission (1994 - 1998) Another boost question.....

[JGheen]

So, I have been reading all these posts about turbo efficency and how much boost is safe to run with a given turbo and have a few questions about my set-up. As my sig states, I am running an HX-35 with the Banks 14cm2 wastegated turbine. With just the Banks set-up and their fuel plate in the stock position, I was making 36 psi max at the manifold. Ever since i installed my 3GSK and #10 plate(about 3/4 to almost full forward) I have been making 38 psi and sometimes even 40 when I let the RPMs get to about 2800 in fourth gear. So with the typical pressure drop from the turbo to the manifold, I would say at the compressor I should be about 40-45 psi. I have heard that the efficency range for the HX-35 is in the 35-38 psi range. So my question is, how long do you think my turbo will live going through the gears at my max boost stated above? The truck is an everyday driver and I never really get on it until the engine is nice and hot, just the way the any engine should be run.

Just asking this question cuz of all the posts on guys blowing 40's up at the pressures I am seeing with my 35. What do ya'll think?

 

[nfox]

Turbo Bark

I think to make a turbo last is try not to have it at max boost and suddenly let off of the fuel peddle all at once thats when the stress is put on to the shaft in the turbo and trys to make it spin backwards and thats what snaps the shaft.

 

[JGheen]

Well, that would be another question I have then. What is the difference in letting off the throttle at peak boost for a shift rather than leaving it in gear and letting off? I always get that loud scream from the turbo after every shift @ 36 psi, well, pretty much at any boost number the higher the louder the scream is. But ever since I have been running the straight pipe, I haven't heard a bark from the turbo like I did with the muffler and resinator installed when I let off the throttle in gear @ max boost. Is barking reduced that much or even permanently with a straight pipe? I would think the backpressure on the turbine would be a sole factor in the rate the turbo would bark after a let off a max boost.